I have a bit of a dilemma and was hoping you guys could help me out. I ride an F4, but build Formula SAE race cars at Ohio State University with an F4i powertrain. I have a few sets of injectors here at the shop, and they have different serial numbers stamped/printed on them. We have also had a few RRs and other bikes in and out, so I am trying to verify they are all in fact F4i injectors.

I know the part number is 16450-mbw-j21, but the serial numbers I have are:
PA13
PK23
PG17

Anyone know anything about these numbers or can confirm them being on their bike at the least? Thanks for any help guys, the team really appreciates it.